Rotary toothbrush



Dec. 31, 1963 A. F. ZERBEE ROTARY TOOTHBRUSH Filed Sept. 27, 1962 United States Patent 3,115,652 RQTARY TOOTHBRUSH Alfonso F. Zerhee, 5914 Coral Sea Ave., Rochville, Md. Filed ept. 27, 1962, Ser. No. 226,598 8 Claims. (Cl. -28) This invention is concerned with power driven toothbrushes. More particularly the invention is concerned with motor driven toothbrushes and improvements there- It is known in the art to provide a rotary toothbrush and to drive the cleaning head by a suitable gear train and power means. An example of such devices, particularly spring motor driven devices, is clearly set forth in US. Patent 1,947,324, issued February 13, 1934 to Alfonso F. Zerbee, and the present invention, by the same inventor, represents an improvement over the structure disclosed therein.

In aforesaid Patent No. 1,947,324 there is disclosed a casing structure and an extension thereof, the former forming the main body portion of the toothbrush and defining a housing for a spring motor assembly, the latter terminating in a socket or bowl-shaped head defining a support for the rotary brushing implement. The spring motor, aside from embracing the usual winding mechanism including a winding key, also includes a gear train and speed governing means to control the brush and motor speed. The structure disclosed therein also includes a shaft carried within the extension portion, driven by the motor and driving, via a right angular gear arrangement, the brush implement, which, in turn, is rotatably mounted within the socket or bowl-shaped terminal end of the extension.

While the brush structure shown in Patent No. 1,947,- 324 and the present invention share many common advantages, the former structure also is possessed of certain disadvantages which are overcome by the improved structure hereof.

Among the common advantages shared by the two structures are complete freedom of use without the necessity of external connections to any power source; freedom from the possibility of electric shock, always a factor of concern where electrically powered implements are used in wet surroundings and, finally; freedom from extensive maintenance since there are very few parts in a spring motor which may require repair, except possibly the drive spring itself.

The disadvantages of applicants prior structure and also, broadly, of the prior art, irrespective of the type of drive mechanism employed, which are overcome by the present invention are numerous. Initially, the drive motors of the prior art devices are often noisy, while the present invention is considerably more quiet in operation. Secondly, difiiculty was and is often experienced with the prior art devices in changing the brushing implement, per se, as, for example, where a single power source is used by the various members of a family, each member having his or her own individual cleaning brush. Additionally, the provision for rewinding the spring motor, if such is used, of the prior art devices are cumbersome and detract from the use and appearance of the implement.

Further, it has been found that more complete cleansing ice cleaning implement is provided with a unique, universal tilting action which improves its cleaning function.

Still another object of the invention is to produce a rotary driven toothbrush which is readily manipulated and easy to clean.

A still further object of the invention is to produce a rotary toothbrush wherein multiple brushes may be readily used interchangeably with a single power source.

These and other objects of the invention, not specifically referred to but inherent therein, are accomplished by providing a main housing or case, a prime mover therein, preferably a spring motor including a releasable winding handle, a motor speed control mechanism comprising a centrifugal brake having spring biased centrifugally extended brake shoes engageable with a non-rotatable or fixed friction resistant portion of a further housing, a tubular extension housing carried by said further housing, said extension terminating in a bowl-shaped socket, a pivot in said socket, brush supporting gear means on said pivot and a brush removable mounted on said gear means, a shaft and gear drive means for the brush supported within the said extension and releasable means for retaining the brush supporting gear means and the brush loosely in position on said pivot for rotary and tilting or wobbling motion thereon while permitting removal of same when desired. Port means are also provided in the extension and socket to facilitate cleaning thereof.

In describing the invention in detail, reference will be made to the drawings attached hereto and forming a part of the disclosure, wherein PEG. 1 is a view of the device as held in the hand of a user,

FIG. 2 is an elevational sectional view taken through the approximate longitudinal center of the forward portion only of the device shown in FIG. 1,

FIG. 3 is a sectional view taken along the line 33 of FIG. 2, and showing the centrifugal, speed regulating brake in an inactive or inoperative condition,

FIG. 4 is a view similar to FIG. 3 but showing the cetrifugal, speed regulating brake in operating condition,

FIG. 5 is a side elevation of the head and brush showing the brush release means in normal brush holding position and, in dotted lines showing the same in releasing position,

FIG. 6 is a perspective view of the back of the brush holding head showing the releasable holding means, and

FIG. 7is a perspective view of a desirable motor energizing handle.

Turning initially to FIG. 1, it may be seen that the invention includes a main body or case portion 10, an intermediate governor assembly 26 and an extension portion St). The case It) is formed of sheet metal, molded plastic or other suitable material, and is preferably formed in two parts having a central parting line similar to that shown in Patent No. 1,947,324. The case 10 is hollow and defines a housing for a spring motor 1 which may be of the type shown in the aforesaid patent. The motor 1 includes a coiled spring, the usual ratchet type of winding mechanism and a suitable gear train wherein the spring energy is converted into rotary motion.

Suitably associated with the case or housing It; so as to be in convenient reach of the users thumb, when the device is held in its usual utility position, is a start-stop lever 2. Lever 2 extends through a slot provided in the housing and is resiliently mounted so as to be movable relative to the housing 10 and one member of the gear train of the motor 1 so that movement thereof will cause a suitable abutment to engage or release the gear train to start and stop the motor. This start-stop mechanism is convenional and amply illustrated in said prior Patent No. 1,947,324.

It will be seen from an inspection of FIG. 7 along with FIG. 1, that one half of the housing 10 is provided with an aperture, not shown, through which projects a shaft 3, which shaft is in turn connected, by conventional ratchet winding means, to the spring motor 1. The shaft 3' is generally centrally located with respect to the housings sides and has a pulley shaped spool 5 fixed to its exposed end. The spool 5 includes a depressed central annular groove 6 and enlarged annular flanges 7, 7. The central groove 6 is diametrically intersected by a pair of coaxial bores 9 and 11 which extend inwardly from the bottom of groove 6 toward the center of the spool 5. The bores 9 and 11 lie in a common plane bisecting the spool 5 midway between the annular flanges 7, 7'.

In slidable engagement with the spool 5 is a crank arm 13. At one end, the crank arm 13 carries a swingable handle 15 connected thereto by a conventional slot and pin connection 14' such that the handle may be moved through an approximately 180 arc in either of two directions and in a single plane bisecting the longitudinal axis of the handle. At its opposite end the crank arm 13 is enlarged somewhat and bifurcated to provide two spaced, parallel fingers 16, 16 which are joined together at their terminal ends by an arcuate bight 17. Centrally located on the bight portion 17 of the crank arm 13 and projecting diametrically inwardly toward the open area defined between fingers 16, 16', is a pin 18, which pin is of a diameter complementary to that of the bores 9 and 11 in spool 5. It will be apparent that fingers 16, 16' are so spaced as to rest in the annular grooved portion 6 of spool 5 and that, because of the generally oval shape of this bifurcated end of crank arm 13 it is bodily movable, along its longitudinal axis, with respect to spool 5. Thus, if the handle 2 is moved in one direction, the bight 17 approaches spool 5 and pin 18 may, by slight rotation of crank arm 13 via handle 15, be caused to drop into one of the bores 9 or 11 and continued rotation of the crank arm 13 will enable the spring motor 1 to be wound. After winding, movement of the crank arm 13' in the opposite direction, longitudinally of its length, will free pin 18 from either bore 9 or 11 and arm 13 may be moved to the position shown in FIG. 1, i.e., generally parallel to the longitudinal axis of the housing 10, whereupon swingable handle 15 is swung through a 180 arc and snapped into locking engagement with a typical resilient clamp 19*.

The above described arrangement serves two functions, first, the handle is locked in an out of the way position as clearly shown in FIG. 1, and second, if the motor 1 is of the type wherein the winding shaft rotates during its operation, the shaft 3 will be free to rotate without interference from the crank arm 13 or without the necessity of having the crank rotate.

Referring further to the drawing, and in particular to FIG. 2, it will be seen that the governing assembly 20 comprises a fixed, annular, cup-shaped housing 21, having a central threaded aperture 22 in the bottom thereof. Disposed within the housing 21 and facing in the opposite direction thereto is a further cup-shaped member 23 comprising a brake drum. This drum 23 is provided at its bottom with a cylindrical sleeve 24 formed integrally therewith and having a threaded exterior 25 which, in turn, forms the connection with motor housing being screwed into a suitably threaded aperture 12 provided therein. The brake drum 23 is fixedly connected to housing 21 by any suitable means. For purposes of simplicity this connection means is illustrated as a set screw S threaded through the housing 21 and abutting against the exterior face of brake drum 23.

The cylindrical sleeve 24 is provided further with a bushing 26, this bushing supporting shaft 27 which extends from within motor housing 10 through the governor section 20 and through extension 30 terminating at the extreme end of the latter as will be more fully described hereafter. At its opposite ends shaft 27 has fixed thereto, by any suitable means, pinion gears 28 and 31, respectively, such that motor 1 may drive the brushing implement.

Suitably mounted upon and fixed to the shaft 27 for rotation therewith is a pair of diametrically opposed, out- Wardly extending pins 23, 23. Slidably mounted on the pins are a pair of segmentally shaped weights 29, 22', having arcuate outer surfaces adapted to engage the inner cylindrical surface of drum 23'. These weights are also provided with central recessed areas 33, 33, respectively, into which the pins 28, 23 project. Bearing against each weight 29, 29', respectively, and the ends of the pins 23, 28, respectively, are small coil springs 32, 32. The springs are biased in compression and are fixed in place surrounding the pins by providing the pins with enlarged heads or by threading nuts and washers on the ends such that the diameter of the ends of the pins exceeds that of these springs 3-2, 32'.

It may be seen, then, that, as long as the shaft 27 is stationary, the weights 29, 29' are biased inwardly toward the center of rotation of the shaft 27 by the springs and they do not contact the inner wall of drum 23. However, as soon as shaft 27 is rotated, the centrifugal force acting on the weights 29', 29' will cause them to move outwardly against the compression forces exerted by springs 32, 32' and the arcuate peripheries thereof will contact the inner wall of brake drum 23 to act as a friction brake slowing down the rotative speed of shaft 27. By a proper selection of the friction area between the weights 2?, 29' and the drum 23 and as well, selection of springs having the proper compression forces, the speed of the motor 1 can be regulated to very close limits. Thus the energy of spring motor 1 is not expended in a single uncontrolled burst of rotation, but rather the energy is expended in a controlled fashion at relatively constant speed over a reasonably long period of time.

As has been set forth, the bottom of the governor housing 21 is provided with threaded aperture 22. Threaded into this aperture, as shown clearly in FIG. 2, is an extension housing and brush supporting assembly 30. Obviously this assembly, like housing 21, is coaxially and concentrically disposed along the longitudinal centerline of the case 18, such that shaft 27 may extend from motor 1 through the device to the cleansing implement.

The extension housing 36* is comprised of a slender, tubular central portion 33 terminating in enlarged ends 35 and 37. End 35 forms a cylindrically shaped base adapted to abut against the bottom of the governor housing 21 and being affixed thereto by means of a threaded sleeve 39 which threadedly engages aperture 22 and which is internally bored or hollowed out to receive a bushing member 41. This bushing supports shaft 27 approximately midway between its terminal ends.

The opposite end 37 of the extension 3%} is in the form of a shallow bowl or socket having its center disposed in an axis normal to the longitudinal axis of shaft 27 and its bottom portion offset but parallel to the latter axis. This bottom portion is provided with a central upstanding spindle 43 which may be formed integrally therewith, the purpose of which will be apparent hereinafter.

As has been stated, shaft 27 terminates adjacent the socket end of extension 30 and is provided with spur gear 31. As seen in FIG. 2, this gear 31 rotates in a plane generally perpendicular to the bottom of the socket 37 and is so disposed with respect thereto that it will mesh with the teeth 49 of crown gear 45 resting on spindle 43 and having a peripheral size closely approximating that of the socket 37. The end of the shaft 27 is supported further in a bushing or hearing 47 suitably fitted into the tubular portion 3 3 of the extension 30. Thus this end of shaft 27, which is somewhat reduced in diameter, as compared to the opposite end carrying pinion 2%}, is firmly supported to assure that the pinion 31 will not whip as the shaft rotates.

Crown gear 4 5 includes a central thickened area which defines a hub 48. The external cylindrical surface 46 of the hub 48 which is concentric with the peripheral gear teeth 49 is threaded to receive the bored and threaded base 51 of the cleaning implement 50 which includes bristles 52 embedded therein.

The opposite side of the hub 48 is provided with a cylindrical recess or bore 53 which receives spindle 4 3 about which the implement 59 rotates.

Upon careful inspection of FIG. 2 it will be noted that the height of spindle 43 exceeds the depth of the recess 53 such that the base of the crown gear 45 is spaced above the bottom of the socket 37. Also the diameter of the bore 53 is greater than the diameter of spindle 43. Thus the crown gear 45 and implement 58 may til-t or wobble on the spindle 43. However, due to the fact that the peripheral teeth 49 of the gear must mesh with pinion 3d, the degree of wobble or tilting is limited to the extent necessary to prevent disengagement of these parts. At the same time, enough freedom of motion is provided so that the crown gear and the implement may be til-ted as a unit to enable its removal from within the bowl shaped socket as the bore 53 is lifted from spindle 43 and gear teeth 49 are disengage-d from pinion 31.

-In order to restrain the crown gear 45 on the spindle 43 and in contact with pinion 31 at all times, the tubular part 33 of extension 30 receives a split collar 55 which grips the exterior thereof tightly, but yet is slidable therealong. The split collar 55 is formed integrally with and supports a narrow connector arm '56 which extends toward the socket portion of the extension 30 and overlies the bottom thereof terminating in a plurality of prongs or fingers 57 which curve around the sides of the socket and have their ends slightly overlying the open peripheral edges of the socket. The ends of the prongs 57 because of the space defined between them prevent the crown gear 45 from falling out of the socket 37 so long as said prongs overlie the open space defined by the socket. At the same time, said prongs prevent the crown gear 45, and hence the cleaning implement Sli, from falling out of the socket, they also permit these elements a certain degree of looseness on spindle 43 so that the desired tilting or wobbling of the crown gear thereon is achieved.

If, however, the split collar 55 is moved on the extension 30 toward the socket 37, it will be seen that the prongs 57 are moved so as to no longer overlie the socket and the cleaning implement 50', along with crown gear 45, may be easily removed and another substituted in its place. It is quite simple, then, to use one power unit as a means of driving individually a selected one of a multiplicity of individual brushes. Further, since the base 51 of the brush 50 is threadedly engaged with hub 46 of crown gear 45, it is quite easy to replace worn out brushes without replacing the crown gear 45.

To facilitate cleaning of the device after each use the socket 37 and extension so are provided with apertures 60 as shown in FIGS. 2 and 6 whereby the cleaning lluid, usually water, may completely enter the socket and the interior of the tubular portion of the extension to cleanse these parts and subsequently be drained therefrom. The bushing 41 may, if necessary, include a sealing means such as an O ring to prevent the cleansing fluid from entering the governor housing 20.

Having thus described my invention, it will be apparent to those skilled in the art that various modifications may be made therein. Such modifications are to be understood as within the spirit and scope thereof, the invention being limited only as defined hereafter, wherein:

What is claimed is:

1. In a power driven rotary brush, a motor housing and a brush supporting extension connected to said motor housing, said extension being tubular and terminating in a bowl shaped socket, a spindle disposed in said socket centrally of the bottom thereof, a crown gear loosely mounted on said spindle and spaced from the bottom of said socket for both rotational movement and tilting movement about said spindle, drive means extending through said tubular extension and engaging said crown gear, means for limiting tilting movement of said crown gear and releasably retaining said crown gear in said bowl shaped socket, and brush means mounted on said crown gear and projecting outwardly from said socket.

2. In a power driven rotary brush as defined in claim 1, said releasable retaining means comprising a collar slidably mounted on the exterior of said tubular extension and a plurality of curved prongs carried by and movable with said collar from a position having their ends overlying the edges of said bowl shaped socket to a position away from the said edges whereby in one first position of said collar said brush and said crown gear are prevented from movement from the interior of the socket and in a second position of said collar, said brush and said crown gear may be removed from said socket.

3.'In a rotary cleaning device a central driven shaft having one end drivingly connected to a power source and the opposite end drivingly connected to a cleaning implement, a plurality of abutting housings surrounding said shaft, at least one of said housings embracing said power source, a further one of said housings terminating in an enlarged bowl shaped socket, a cleaning implement loosely mounted in said socket and connected to said shaft for rotation thereby, and releasable means carried by said last-mentioned housing for retaining said cleaning implement in said socket, said releasable means comprising means sli'dably engageable with said last-mentioned housing, movable toward and away from said socket, and means carried by said slidable means and overlying the edge of said socket in one position to retain said cleaning implement positioned within said socket when said slidable means is in said one position.

4. In a cleaning device as defined in claim 3 wherein said socket includes a spindle and said cleaning implement comprises a crown gear mounted on said spindle and spaced from the bottom of said socket, brush means removably mounted on said crown gear, and wherein said shaft carries at its terminal end a pinion gear engageable with said crown gear.

5. In a rotary cleaning device having a plurality of coaxial, abutting housings, a common central shaft extending into each of said housings and means for driving said shaft disposed in one of said housings, and dental hygiene implement means disposed in a further one of said housings; the improvement wherein said last-mentioned housing terminates in an enlarged bowl-shaped socket provided with a central spindle projecting upwardly from the bottom of the socket toward the interior thereof, said dental implement means being provided with a central recess engageable with said spindle to support said implement for both rotational and universal tilting motion on said spindle, peripheral gear teeth means carried by said implement and extending upwardly away from the bo tom of said socket, a driven spur gear carried by said central shaft disposed in said socket and in engagement with said gear teeth means, and means carried by said socket and engageable with the implement to prevent dislodgment of the implement from said socket when in one position while permitting removal of said implement from said socket in a further position.

6. In a rotary cleaning implement as defined in claim 5, wherein said dental hygiene implement comprises a crown gear rotatably and tiltably mounted on said spindle and including said gear teeth means, said crown gear including a central hub having a threaded exterior and a base member having bristles embedded therein, on one surface, and a central threaded bore provided in the opposite surface, said bore being threadedly engaged with said crown gear hub.

7. For use in a rotary cleaning implement including a housing having a drive means therein and a central driven shaft connected to said drive means, an elongated extension member surrounding said shaft and engageable with said housing at one end, the opposite end of said extension member terminating in a shallow bowl-shaped socket, spur gear means mounted in said socket and driven by said shaft, a cleaning implement rotatably and tiltab ly mounted in said socket and in engagement with and driven by said spur gear, means carried by said housing and engageable 'With said socket and including means extending in overlying relation with respect to the peripheral edge of said socket preventing dislodgmen-t of said cleaning implement from said socket when in one position and errnitting release of said implement from said socket in a further position.

8. For use in a rotary cleaning implement, an elongated extension as defined in claim 7 wherein said bowlshaped socket and that portion of said extension surrounding said shaft are provided with spaced apertures to facilitate flushing and cleaning of the socket and the interior of the extension after use.

References Cited in the file of this patent UNITED STATES PATENTS Gibney Aug. 1.7, 1915 Reiche Jan. 4, 1916 Frame Jan. 18, 1921 Starkey Mar. 22, 1921 Bailey Apr. 8, 1924 Zerbee Feb. 13, 1934 Smith June 6, 1939 Cazes June 18, 1940 Sussman Oct. 21, 1941 Gregoire Oct. 8, 1957 FOREIGN PATENTS France May 27, 1946 France Nov. 17, 1958 

1. IN A POWER DRIVEN ROTARY BRUSH, A MOTOR HOUSING AND A BRUSH SUPPORTING EXTENSION CONNECTED TO SAID MOTOR HOUSING, SAID EXTENSION BEING TUBULAR AND TERMINATING IN A BOWL SHAPED SOCKET, A SPINDLE DISPOSED IN SAID SOCKET CENTRALLY OF THE BOTTOM THEREOF, A CROWN GEAR LOOSELY MOUNTED ON SAID SPINDLE AND SPACED FROM THE BOTTOM OF SAID SOCKET FOR BOTH ROTATIONAL MOVEMENT AND TILTING MOVEMENT ABOUT SAID SPINDLE, DRIVE MEANS EXTENDING THROUGH SAID TUBULAR EXTENSION AND ENGAGING SAID CROWN GEAR, MEANS FOR LIMITING TILTING MOVEMENT OF SAID CROWN GEAR AND RELEASABLY RETAINING SAID CROWN GEAR IN SAID BOWL SHAPED SOCKET, AND BRUSH MEANS MOUNTED ON SAID CROWN GEAR AND PROJECTING OUTWARDLY FROM SAID SOCKET. 